Wavelength and kinetic energy of crystally diffracted neutron beam.

Oct 2016
2
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A beam of neutrons all with the same energy are diffracted by atoms which are seperated by 0.0910 nm in a crystal plane.

At the angle $\theta = 28.6^{\circ}$ the instensitymaxima for $m=1$ is observed.
What is the neutron wavelength and the kinetic energy expressed in eV?